Many processes are known in the art for the carbonylation of olefinically and acetylenically unsaturated compounds. A review of such processes is provided by J. Falbe, "New Syntheses with Carbon Monoxide", Springer-Verlag, Berlin Heidelberg New York, 1980. Typically the processes involve the reaction of an olefinically unsaturated compound with carbon monoxide and, in some cases, hydrogen or a nucleophilic compound having a removable hydrogen atom, in the presence of a carbonylation catalyst system. In many instances, the carbonylation catalyst system comprises a source of a Group VIII metal and a ligand such as a phosphine.
One type of catalyst system which has been disclosed in recent years comprises a source of a Group VIII metal and a pyridyl phosphine.
Kurti Kurtev et al, Journal of the Chemical Society, Dalton Transactions, 1980, pages 55 to 58, discloses catalyst systems comprising a rhodium or ruthenium compound and a pyridyl phosphine, and their use in the carbonylation of hex-1-ene.
U.S. Pat. No. 4,859,764, issued Aug. 22, 1989, discloses catalyst systems comprising a palladium compound, a pyridyl phosphine, an acid and a quinone and their use in the carbonylation of olefins to afford polymers.
European patent application publication number EP-A1-0271144, filed Nov. 25, 1987, discloses the use of catalyst systems comprising a palladium compound, a pyridyl phosphine and an acid in the carbonylation of acetylenes with hydroxyl-containing compounds.
U.S. Pat. No. 4,786,443, issued Nov. 22, 1988, discloses the use of catalyst systems comprising a palladium compound, a pyridyl phosphine and an acid in the carbonylation of olefins with hydroxyl-containing compounds.
None of the aforementioned references describes experiments in which a catalyst system comprising a (substituted-pyridyl)phosphine is used. However, European patent applications publication numbers U.S. Pat. No. 4,859,764, issued Aug. 22, 1989 and U.S. pat. No. 4,786,443, issued Nov. 22, 1988, contain lists of phosphines. All of the listed phosphines possess a heterocyclic substituent attached to phosphorus which is either unsubstituted or substituted with a halogen atom or an alkoxy group. No method is described for the preparation of any of these phosphines, nor are any physical characteristics of any of the phosphines provided. All of the phosphines described in the working examples possess an unsubstituted heterocyclic group attached to phosphorus.
Newkome et al, J. Am. Chem. Soc., 100 (17), 5567-8, discloses bis(6-ethoxy-2-pyridyl)phenyl phosphine, bis(6-chloro-2-pyridyl)phenyl phosphine, and bis(6-bromo-2-pyridyl)phenyl phosphine. It also discloses a bis(2-pyridyl)phenyl phosphine wherein the two 6-positions of the pyridyl groups are linked by a chain of formula O(CH.sub.2 CH.sub.2 O).sub.5 CH.sub.2 CH.sub.2 O.